Blower wheel blade finger expansion mounting



Dec. 21, 1965 v. E. SPROUSE ETAL 3,224,669

BLOWER WHEEL BLADE FINGER EXPANSION MOUNTING IFI Er: 9

Filed Jan. 22, 1965 IFIE;

HNvENTuns VERNER E. SPRDUSE. VERNDN H.WlLLlAl\/1S ATTURNEY United States Patent 3,224,669 BLOWER WHEEL BLADE FINGER EXPANSION MUUNTING Verner TE. Sprouse and Vernon H. Williams, Columbus,

1nd, assignors to Vernco Corporation, Columbus, 11111.,

a corporation of Indiana Filed Ian. 22, 1965, Ser. No. 427,382 4 Claims. (Cl. 230-434) This invention relates in general to air moving devices, and in particular to a blower wheel commonly used in refrigerating and heating devices. In such blower wheels, there is commonly employed a back plate through which the wheel is driven; an outer ring encircling an air inlet and a plurality of blades secured by end portions respectively to the back plate and the ring. Generally the blades will have a transverse curvature, the degree of curvature varying with different designs of the Wheels. The particular degree of curvature does not enter into the present invention per se.

Many combinations of attachments of the blades with the back plate and ring or as is sometimes called the front plate have been devised. The tendency has been to increase the number of revolutions per minute in order that the overall diameter and axial length of the wheel may be kept to a minimum particularly in view of the fact that such blower wheels are employed in designs having limited space for the wheel.

The invention described and claimed herein involves, in general, a number of fingers extending from ends of the blades and these fingers are passed through circular holes in the back plate and ring. The transverse widths of the fingers are greater than the diameter of the holes, and therefore these fingers have to be deformed to reduce the transverse width to get them through the holes. Then the fingers are tended to be flattened while in the holes so as to force the side edges of the fingers into compressive contact with the margin of the hole in each case.

With that feature of the invention in mind, it is a primary object of the invention to provide a rigid engagement of members of opposite ends of individual blades with the back plate and ring in such a manner, that the rigidity of interconnection will be maintained at speeds such as around 3,000 revolutions per minute, this particular figure being as an example, and not a limitation.

It is a further primary object of the invention to provide such interconnection between the blades and back plate and the ring to maintain the wheel with desired alignment in respect to the two plates and the axes of the individual blades so that neither the back nor the ring will be advanced or retarded one from the other in normal action, in respect to rotation of the wheel, in order to maintain the desired alignment of the individual blades in respect to the axis of rotation.

A further important object of the invention resides in the fact that no complicated devices are required in the formation of the blades, and neither is any complicated method required to assemble the blades with the back plate and ring.

These and other objects and advantages of the invention will become apparent to those versed in the art in the following description of one particular form of the invention as now best known to us, as illustrated in the accompanying drawings, in which FIG. 1 is a view of a side elevation of a blade to be employed in the present invention;

FIG. 2 is a view in one end elevation;

FIG. 3 is a view in opposite end elevation;

FIG. 4 is a fragment of the blower wheel in elevation as viewed from the air intake end;

3,224,669 Patented Dec. 21, 1965 FIG. 5 is a view of the end of the blade on an enlarged scale with a finger inserted through a hole of the end ring;

FIG. 6 is a view in end elevation similar to that shown in FIG. 5 and with the finger bent over against the outside face of the ring;

FIG. 7 is a view in section on the line 7-7 in FIG. 6;

FIG. 8 is a view in section on the line 8-8 in FIG. 6; and

FIG. 9 is a view of the completed blower wheel in side elevation on a reduced scale,

A blade generally designated by the numeral 10 is formed to have a desired transverse curvature. A finger 11 extends integrally from one end of the blade 10, and two fingers 12 and 13 extend from the other end of the blade. The single finger 11 on the one end extends intermediate the edges 14 and 15 of the blade 10, and the other fingers 12 and 13, extend from the blade end in spaced apart relation. Each of the fingers 11, 12 and 13-, are reduced in their original flat form to a substantially V-shape, an apex of the V being indicated on the respective lines 16, 17, and 18.

The back plate 19 is provided with a pair of circular holes 26) spaced apart laterally a distance equal to the land 21 of the blade 10, this land 21 having an extent equal to the spacing apart of the fingers 12 and 13 at their junctures with the blade 10. The ring 22 is provided with a series of single holes 23 spaced circumferentially around the ring as indicated in FIG. 4. It is to be noted that the pairs of circular holes 21) are spaced circumferentially around the plate 19, with spacings of the holes 20 being equivalent to the spacing apart of the holes 23.

All of the holes 20 and 23 have a diameter, for eX- ample, of 1 of an inch in one particular size of wheel, this diameter being variable depending upon the size of the wheel to be produced. Each of the fingers 11, 12, and 13 when in their flat conditions before the V formation has a width adjacent the ends of the blade of 7 of an inch. It is evident that the tonque having a 7 inch width will not pass through the hole having a inch diameter. Therefore, each of the fingers are folded sufficiently into the V shape to allow them to pass freely through the respective holes.

The fingers 11, 12 and 13 have lengths exceeding the thicknesses of the plate 19 and also of the ring 22, to have lengths sufiicient to permit them to be bent over onto the outer side respectively of the plate and ring members. These fingers in each instance, while the plate and ring are held tightly against the ends of the blades 10, are bent over on their respective outer sides of the plate and ring as indicated in FIG. 6. In this overbending action, the fingers are tended to be restored to their original flat shape, or to the shape of the curvature of the blade at the zones from which the fingers extend, so that the fingers will tend to be restored to their original width causing the edges of those fingers to bear COrnpressively against the margins of the various holes, and in fact tend to bite into the margin of each hole at its diameter and the finger is carried down against the outer Surfaces of the plate and ring as best indicated in FIG. 8.

It is to be noted that in forming the V shape of the fingers 11, 12 and 13, there is produced what may be termed a dimple 25 in the end of the blade 10 as a terminal extension of the fold of the finger in each instance on their respective bend or apex lines 16, 17, and 18. When the fingers are bent over onto the ring 22 and plate 19, there will be a head 26 in each instance automatically formed over the lines 16, 17 and 18, around the bend 27, FIG. 8, and extending substantially out to the free end portion 28 of the finger. The fingers then come into initial contact with the ring 22 and plate 19, with a yielding spring contact, particularly by the end portions 28.

The area of contact between the fingers and the ring and plate may be increased from the end portions 28 back toward the holes 23 and by increased bending pressure, but the fingers in any event will exert to some degree at least, a yielding pressure on the ring and plate urging one toward the other to grip the blades 10 by their opposite ends which extend laterally from the fingers.

In this construction, the beads 26 which extend around the bend zones and onto the fingers, reinforce the bends to produce a stiffening effect effectively resisting reverse bending of the fingers and thereby maintain their continuing pressure on the ring and plate. Not only is this result obtained, but also the bead aids in maintaining a continuous pressure laterally of the fingers to prevent reduction of pressure between the side edges of the fingers and the walls of the holes. The fingers 11, 12 and 13 are, in the bending operation brought into substantially a fiat condition, with the beads 26 extending centrally thereof from the blades toward the finger end portions 28.

This formation gives an exceedingly rigid interconnection between the blades and their plate and ring, particularly in view of the fact that the ends of the blade on each side of the various fingers are in parallelism with the plate and ring and the overturned portions of the fingers maintain the plate and ring in compressive engagement with the respective ends of the blade.

While the foregoing description has been made primarily in reference to the single finger 11, the same operation is had at the plate where there are the two fingers 12 and 13, each passing through adjacent holes 20, and then flattened out in the bending over action. The two holes and two fingers at the plate increase the rigidity of attachment thereto of the blades over and above the usage of a single hole and a single finger and hold the blades against rotation on their individual axes.

Thus it is to be seen that a blade having fingers extending from its opposite ends and having original widths greater than the holes through which they are to be inserted can be inserted readily by laterally bending the fingers suificient to reduce their width temporarily thereby permitting quick and easy assembly of the blades between the back plate and the ring. Furthermore, this action of tending to increase the transverse widths of the fingers after insertion through the holes, sets up a toggle action as the blade is flattened out in its bending to right angle positions with the blades 10.

The bentover end portions of the fingers 11, 12 and 13, may be left in that bentover position without further securing means, or they may be secured both to the plate and the ring or selectively one or the other, by any such means as by welding, soldering, brazing, and the like which, however, introduces a problem in balancing the wheel. Of course, if desired, a fiat finish plate may be laid over the bentover fingers around the outer side of the ring 22 and likewise the outer side of the plate 19, such rings not being shown since they would not enter per se into the invention.

While we have herein shown and described our invention in the one best form as now known to us, it is obvious that structure variations may be employed, without departing from the spirit of the invention, and we therefore do not desire that the invention be limited to this precise form beyond the limitations as may be imposed by the following claims.

We claim:

1. In a blower wheel, the combination with a plurality of blades;

a back plate;

a ring; and

a plurality of blades between the plate and ring; of

a finger extending from each end of each blade;

said plate and said ring each having finger receiving,

circular holes therethrough;

each of said fingers having the thickness of one of said blades and a normal width exceeding the diameter of said holes;

said fingers having initially a V-shape with a central Zone extending longitudinally of the fingers providing a projected finger width less than the diameter of said holes;

said fingers extending through and beyond said holes;

an approximately fiat finger end portion extending from each hole into intimate contact with adjacent areas of the plate and ring;

a bead extending along said zone through said hole in each instance;

the fiat end finger portions inducing a lateral extension of the fingers in the holes; and

there being bead maintaining stress on the finger portions to each side of the bead, continuously holding the longitudinal edges of the fingers in firm contact with diametrically opposite sides of the holes.

2. The method of interengaging blades with a back plate and a ring by fingers, which method comprises making circular holes around the plate and the ring, axially aligned and spaced apart to determine the spacing of the blades;

forming blades with at least one finger extending longitudinally of the blade from opposite blade ends; with finger widths exceeding the diameter of said holes; the finger width being less than that of the blades to leave a shoulder on the blade at a side of the finger;

folding each finger into an obtuse angle along a line extending centrally, longitudinally of the finger to reduce the projected width of the finger to less than said hole diameter;

inserting the folded fingers through respective holes in both the plate and the ring;

bending ends of the fingers projecting from the holes in common directions from the obtuse angle sides over and down against respective plate and ring areas adjacent the holes;

said bending action automatically returning the folded fingers approximately to their original widths causing the side edges of the fingers to bite compressively into diametrically opposite zones of the holes;

said bending action setting up a bead to rise along the fold line of said obtuse angle through building up of resistance of travel of the said finger edges into the marginal zone of the holes; and

said head retaining pressure of said finger edges on said zones.

3. The method of claim 2, in which said beads extend from the blade ends and around the bends of the fingers through said round holes and merge into the bent over ends of the fingers and maintain said finger edges in compressive contact with said zones; said ends being approximately fiattened in said bending.

4. The method of claim 2, in which each end of each blade is dimpled at the ends of said finger longitudinal line limiting extension of said head into the blade.

References Cited by the Examiner UNITED STATES PATENTS MARK NEWMAN, Primary Examiner. 

1. IN A BLOWER WHEEL, THE COMBINATION WITH A PLURALITY OF BLADES; A BACK PLATE; A RING; AND A PLURALITY OF BLADES BETWEEN THE PLATE AND RING; OF A FINGER EXTENDING FROM EACH END OF EACH BLADE; SAID PLATE AND SAID RING EACH HAVING FINGER RECEIVING, CIRCULAR HOLES THERETHROUGH; EACH OF SAID FINGERS HAVING THE THICKNESS OF ONE OF SAID BLADES AND A NORMAL WIDTH EXCEEDING THE DIAMETER OF SAID HOLES; SAID FINGERS HAVING INITIALLY A V-SHAPE WITH A CENTRAL ZONE EXTENDING LONGITUDINALLY OF THE FINGERS PROVIDING A PROJECTED FINGER WIDTH LESS THAN THE DIAMETER OF SAID HOLES; SAID FINGERS EXTENDING THROUGH AND BEYOND SAID HOLES; AN APPROXIMATELY FLAT FINGER END PORTION EXTENDING FROM EACH HOLE INTO INTIMATE CONTACT WITH ADJACENT AREAS OF THE PLATE AND RING; A BEAD EXTENDING ALONG SAID ZONE THROUGH SAID HOLE IN EACH INSTANCE; THE FLAST END FINGER PORTIONS INCLUDING A LATERAL EXTENSION OF THE FINGERS IN THE HOLES; AND THERE BEING BEAD MAINTAINING STRESS ON THE FINGER PORTIONS TO EACH SIDE OF THE BEAD, CONTINUOUSLY HOLDING THE LONGITUDINAL EDGES OF THE FINGERS IN FIRM CONTACT WITH DIAMETRICALLY OPPOSITE SIDES OF THE HOLES. 